COMMUNICATION SYSTEM, COMMUNICATION METHOD, COMMUNICATION DEVICE, AND COMMUNICATION PROGRAM

摘要

PROBLEM TO BE SOLVED: To suppress a communication cost and enhance security.SOLUTION: A first communication device generates key data by performing processing including selection of one or more arithmetic procedures from a plurality of different arithmetic procedures on the basis of the time common to the first communication device and a second communication device, encrypts data by using the generated key data and transmits the encrypted data to the second communication device. The second communication device generates key data by performing processing including selection of one or more arithmetic procedures from the plurality of arithmetic procedures on the basis of the common time, and decrypts the encrypted data received from the first communication device by using the generated key data.